An industrial machine in a form of a machine tool configured to machine (e.g., cut) a workpiece set on a table with a tool by moving the table and the tool in a plurality of axial directions has been known.
When the workpiece is machined with the tool, cut powders are generated. When the cut powders enter between sliding surfaces of relatively movable members of the machine tool, various disadvantages are caused.
The table on which the workpiece is set includes a table base. The table base is movable relative to a table bed extending in a horizontal axis (X axis) while sliding on a reference plane of the table bed. Cut powders generated during machining the workpiece are likely to be accumulated on a top surface (the reference plane) of the table bed. The cut powders fall along a vertical surface (the reference plane) of the table bed by gravity. The fallen cut powders cause a lapping phenomenon between a cast quenching surface of the table bed and a resin sliding material of the table base to influence a large range of the sliding surface.
For this reason, a countermeasure against inhibiting the cut powders from entering between the sliding surfaces of the two relatively movable members is applied to the machine tool.
The countermeasure against the cut powders is exemplified by a cut-powder discharge device including a column fixed to a base frame and a table movable along a Y axis of a bed, in which the cut powders on a table rear surface are transferred to a chip conveyor using the movement of the table along the Y axis and the cut powders are discharged to the outside using the chip conveyor (Patent Literature 1).
In the above typical example of Patent Literature 1, the table is provided to the bed through a saddle. The saddle is movable along the Y axis relative to the bed. A gutter-shaped recess is formed along the Y axis on a top surface of the bed. The saddle includes a wiper shaped in conformity to the recess. By the movement of the table along the Y axis, the wiper discharges the cut powders fallen in the recess of the bed to a U-shaped groove of a screw conveyor. The wiper inhibits the cut powders from entering between sliding surfaces of the saddle and the bed. The column is attached with a spindle head, a tool replacement device and the like.
Another example of the countermeasure against the cut powders is a sliding-surface protection device including: a screen cover that covers a front side and lateral sides of an X-axis sliding surface of a lower saddle; and a cutting-liquid nozzle provided in the screen cover (Patent Literature 2).
In the typical example of Patent Literature 2, when a cutting liquid is supplied to the sliding surface by the cutting-liquid nozzle, fine cut powders on the sliding surface are washed away.
Although not an example of the countermeasure against the cut powders, an elevator including a device configured to discharge abrasion powders and chips generated on the sliding surface to the outside is disclosed (Patent Literature 3).
In the typical example of Patent Literature 3, a groove is provided on a sliding surface of a damper for stopping at emergency and the abrasion powders and the like are discharged from the groove to the outside to prevent abnormal abrasion of components. The groove extends in a direction orthogonal to a longitudinal direction of a guide rail of the damper on a damping surface facing the guide rail. Both ends of the groove are opened.
Further, in machine tools, a lubricating oil is flowed along an oil groove in order to prevent abrasion of the two relatively movable members (Patent Literatures 4 to 6).
A typical example of Patent Literature 4 discloses a device configured to supply the lubricating oil on a sliding surface of a T-slotted rail. In a typical example of Patent Literature 5, a saddle is slidably supported on a guide surface of a slide base and includes an oil groove on a surface facing the slide base. In a typical example of Patent Literature 6, a middle table includes an oil groove, which is configured to supply a lubricating oil, on a sliding surface facing a saddle.